well I got a reply from ubisoft, nice chap by the name of William, I explained the problem I was having... here was what I had said.... when I start the game it runs fine, loads fine and plays fine, loads my save no problem, and allows me to play via keyboard, but the moment I switch control on everything goes to pot, if im already in the game, it gets very jittery, using vehicles have a severe lag, crash into anything and everything. missions wont start with controller going. start the game running with control on it starts to load, but stops once it gets to screen where it tell you NOT to switch off when save symbol is on,, press control centre button it then jolts the game to next screen, but that is where I have to do the same thing to do anything else, get it to start screen, (online/offline etc..) tell it to load my save, got to press centre button to get it to start loading the save, blank screen, so again press centre button, game EVENTUALLY loads, start playing it just jitters and same again use vehicles TRY to switch weapons and it just doesn't work properly, eventually get to a mission point and it freezes up, centre button again, eventually loads, starts the mission and just doesn't work properly, kills me off for no reason, sends me in different directions with lag....

to this and after I sent msinfo and dxdiag info it turns out my controller drivers are the problem, its nothing to do with the game itself, but my drivers for the device I use to connect xbox control, which was highly recommended to me, would seem it done an update which has messed my controller up. as I had stated to William game works 100% until I connect the controller. here is one of his replies.... Thank you for the information and for the files.

I was able to investigate this issue further and I can confirm the issue you are experiencing is due to an incompatibility with the latest drivers of the Xbox 360 controller and the game.

The issue is currently under investigation by our Developer team, but unfortunately we have not found a solution that can be applied on our side yet. It is likely that a future update for the Xbox 360 drivers could resolve the issue, however we are unable to guarantee this.

For the time being, please remove the controller when playing FarCry 4 in order avoid the issue. You should still be able to play the game using your mouse and keyboard. I asked for clarity on what he was meaning, now when you say latest drivers for controller do you mean as in the device I use to connect my controller or a controller update your guys made?

his reply Regarding your last question, the issue is related to the actual controller driver software that manages your device. The driver will likely need to be updated in order to offer compatibility with the new PC games. These updates are usually provided by Microsoft.

now I know this post may not be allowed but hope it will be left... this may not be the same issue any1 else is having, but thought I should at least let others who MAYBE having similar issues that this could possibly be your answer your looking for.....